PUSH_PROMISE associated stream

 From 6.6 PUSH_PROMISE:

PUSH_PROMISE frames MUST be associated with an existing, peer-initiated 
stream. If the stream identifier field specifies the value 0x0, a 
recipient MUST respond with a connection error (Section 5.4.1 
<http://http2.github.io/http2-spec/index.html#ConnectionErrorHandler>) 
of type PROTOCOL_ERROR 
<http://http2.github.io/http2-spec/index.html#PROTOCOL_ERROR>.

Is this a vestigial carry-over from SPDY? I don't see an 
"Associated-To-Stream-ID" field in PUSH_PROMISE. At first glance, it 
looks like HTTP/2 does away with requirement that a pushed resource be 
associated with a client-initiated stream.